Data cable for high-speed data transmissions

Abstract

A data cable for high-speed data transmissions includes at least one wire pair formed of wires extending in a longitudinal direction and being surrounded by a shielding foil to form a pair shielding. A dielectric intermediate film or foil having a varying lay length is spun around the wire pair between the shielding foil and the wire pair, in order to effectively avoid a damping peak at high transmission frequencies.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This is a continuation application, under 35 U.S.C. §120, of copending International Application PCT / EP2015 / 065034, filed Jul. 1, 2015, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2014 214 726.3, filed Jul. 25, 2014; the prior applications are herewith incorporated by reference in their entirety.BACKGROUND OF THE INVENTIONField of the Invention[0002]The invention relates to a data cable for high-speed data transmissions, including at least one wire pair formed of two wires extending in a longitudinal direction and being surrounded pairwise by a shielding foil in order to form a pair shielding, and a non-conductive intermediate film being spun around the wire pair as an additional film between the shielding foil and the wire pair. Such a data cable is being offered for sale by Leoni Cables and Systems of San Jose, Calif. under the brand name “23 Para...

AI Technical Summary

Benefits of technology

[0012]It is accordingly an object of the invention to provide a data cable for high-speed data transmissions, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known cables of this general type and which has good transmission properties even at high transmission rates and high transmission frequencies.

[0015]In principle, there would be the possibility to shift the attenuation frequency toward higher frequencies by geometrical measures such as, for example, a shorter length of lay. In the ParaLink cables described in the introduction, this is obtained by a very steep pitch of the winding. The length of lay in this case is, in particular, approximately 3 mm, so that the peak-type insertion loss and hence also the return loss lies above 25 GHz. According to the currently applicable standards, such a peak in such lines must not occur within the frequency range up to 25 GHz. However, due to the more intense wrapping, the short length of lay results in a low processing speed in the course of the wrapping of the pair of wires, leading to higher costs.

[0016]Accordingly, in conventional data cables with the intermediate film, a comparatively large attenuation (attenuation peak) occurs by reason of the addition of all of the individual reflections at a fixed, narrow frequency. As a result, a high attenuation of the signal occurs, so that the requirements of the so-called insertion loss for high transmission frequencies are only inadequately satisfied. In contrast, by reason of the varying length of lay, an attenuation peak is no longer present at a fixed frequency, so that the requirements of the insertion loss are even satisfied at high frequencies. At the same time, as a result there is the possibility to lengthen the length of lay and hence to increase the processing speed and consequently lower the costs.

[0019]The mean length of lay of the intermediate film in this case preferentially lies within the range of a few millimeters, in particular within the range from 5 mm to 15 mm. In particular, the mean length of lay in this case lies approximately between 6 mm and 8 mm. With this length of lay, a fast and reliable production of the wrapping of the intermediate film, in terms of process engineering, is made possible. A high processing speed is achieved. At the same time, the properties desired with the intermediate film can be obtained in this way, namely a defined, fixed wrapping of the pair of wires, in order to place the shielding foil attached over it in a defined uniform geometry around the pair of wires, so that no symmetrical points of interference of the shielding foil have been formed.

Problems solved by technology

This results, therefore, in a high attenuation peak at high frequencies in the case of the so-called insertion loss.

By virtue of the periodic structure, in addition this also results in a high attenuation peak at high frequencies in the case of the so-called return loss.

However, due to the more intense wrapping, the short length of lay results in a low processing speed in the course of the wrapping of the pair of wires, leading to higher costs.

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